Idling problem (with video link)

Hi,

I have poor idling in my bike when (fully) warm. Carbs are clean and synced.

Here's a short video
https://www.dropbox.com/s/f8s1xm9ivvkp7ge/20200610_214221_2%5B1%5D.mp4?dl=0

All ideas / comments welcome. I'm suspecting ignition, maybe when the coils are warm they start to fail? I'm running CBR1000RR stick coils but probably they can fail too?

my personal opinion is a misfire

You can check resistance between both connections of each coil according to cbr1000 service manual.

Also test with other coils from a friend or even test with the original ones.

test with other spark plugs and check coils installation connections.

in the absence of the above, remove a spark plug and ground it. with only the other engine start, perhaps it will be discovered that the coil fails



luck !!

Possible but unlikely, coil failure would be constant. 
Is the choke coming off completely? 
Your mixture may be weak, if it runs ok when cold and the choke richens the mixture. This ethanol causes a weak mixture and if you've cleaned the carbs you may need to richen it by adjusting the mixture screw.

increasing it of revolutions beyond the idle I believe that it will be seen if it is failure in carburation .......

You can also empty the carburettors cube to test with only fresh gasoline....

Thanks for your comments.

Went for a ride today and things got worse, misfiring also below 3k rpm.

I stopped by the road and removed right hand side coil while engine running -> engine runs with left cylinder. Re-install right hand side coil -> bad idle. Remove left hand coil -> engine dies.

I went back home and swapped coils left to right & vice versa. Engine idles poorly. Remove right hand side coil -> engine dies. Re-install coil and start engine, remove left hand side coil -> engine runs with right cylinder.

I don't think there are other options than bad coil.

I also measured primary & secondary resistances, but do not have reference for what would be acceptable range for CBR1000RR.

Good coil
Cold
Pri 1.8ohm
Sec 12.8kohm

Warm
2.0o
17ko

Bad coil
Cold
1.6o
8.65ko

Warm
2.1o
11.8ko

Anyway I found a Finnish bike breaker listing 2 pieces of used 929 coils for 50eur so off to interwebz-shopping then...

Received 929 coils today.

I measured them (cold) before installing

1.4ohm
11.46kohn

1.3ohm
11.41kohm


Went for a ride and everything is OK. Also improved acceleration at upper rev range so most probably there was intermittent misfiring also at higher revs with the bad coil.

without knowing which are the correct figures according to manual, the fact that both are almost the same seems positive to me ..... but the fault is there ... and since the price of a used spare part is 'acceptable' I would try other coils


more: I have looked on the internet two manuals of cbr1000rr post 2000 and it does not give values ​​of coils but it refers to checking in switchboard connectors .. bad vibes so much modernity supertech !

Burudi: my bike runs perfectly now with the "new" coils.

Perhaps in the old bad coil there is some soldering or other bad connection which starts to fail when the coil warms up.

perfect

Again!

Went for a ride, limped home with about 1.5 cylinders.

Don't know what caused the second coil failure but the connection between coil and spark plug was a bit loose so that might have caused extra load on the coil.

New plugs, mix'n'match 2 best coils (one CBR929 and one CBR1000) and the bike seems OK, although the true test will be when I take it for a ride.

I checked the connection between coil connectors and CDI unit, all OK
CDI ground OK
Battery voltage about 14.3 @ 5000rpm with high beam on (OK according to Haynes).

Annoying. Don't envy you. Hopefully you get to the bottom of it sharpish.

I went ahead and ordered a pair of brand new 929 coils, 155 eur shipped. Hopefully they are the last ones I need to buy.